A Soil-Pile Response under Coupled Static-Dynamic Loadings in Terms of Kinematic Interaction

Abstract

Although the axial aptitude and pile load transfer under static loading have been extensively documented, the dynamic axial reaction, on the other hand, requires further investigation. During a seismic event, the pile load applied may increase, while the soil load carrying capacity may decrease due to the shaking, resulting in additional settlement. The researchers concentrated their efforts on determining the cause of extensive damage to the piles after the seismic event. Such failures were linked to discontinuities in the subsoil due to abrupt differences in soil stiffness, and so actions were called kinematic impact of the earthquake on piles depending on the outcomes of laboratory tests and other numerical analyses. In this research, numerical modeling is used to explore the kinematic forces created in a single pile erected in two sand layers under two different conditions (dry and saturated states). Based on the obtained results from the physical model, the maximum bending moment was observed at a depth around 200 mm below the ground surface in the loose sand layer, then these values gradually reduced until it becomes negative in the dense sand layer. It has been demonstrated that this modeling may be used to predict how a pile foundation would respond to “kinematic” loading generated by ground movements during a seismic event. Consequently, the current findings could be used in the design and construction of bored aluminum or steel piles in Al-Karbala soil.

Numerical Assessment of Pipe Pile Response under Seismic Excitation

“…The maximum bending moment under the influence of a couple of static and seismic loads is shown in Figure 2 for both saturated and dry circumstances. The saturated sandy soil's bending moment values were higher than the dry one (as presented in Table 3), which could be a result of the liquefaction event [4], the liquefaction propagation in the loose sand layer occurred shortly after the maximum value of the bending moment was attained. In the subsequent work, Hussein and El Naggar [19] found a similar pattern when testing a helical pile placed in saturated sand soil.…”

“…Some researchers claimed that the pile might act in an unpredictable manner because of the development of excess pore pressure, resulting in weak saturated soil and, as a consequence, a significant bending moment and shear stress on the pile [3]. Because of the formation of additional pore pressure in saturated soil, the pile shaft stiffness reduces throughout a seismic event and may evaporate after an assessment of ground shaking with the excess pore pressure [4,5]. The axial load variation contributes to withstanding the bending moment generated by the soil's lateral loading, while the vertical pile displacement is caused by the fluctuation of its vertical loads [6].…”

“…The computer modeling analysis showed that the building weight controls the inertial force while pile spacing has very little impact on kinematic forces. The term "inertial component" refers to the moment resulting from inertia forces, whilst the term "kinematic component" refers to the moment developed by soil movement [4].…”

Data-Driven Prediction of Maximum Settlement in Pipe Piles under Seismic Loads

“…The prediction technique has been applied to estimate damage progression, mixedmode fracture, and fatigue durability (as indicated in [27][28][29][30]). This predictive approach facilitates future engineering judgments by selectively sampling from the available data set in a wide range of phenomena, including engineering science.…”